Thomas j



(No Model.)

T. J. HOGAN.

AIR BRAKE. No. 433,594. Patented Aug. 5, 1890.

FIGJl.

INVENTOR,

WITNESSES:

'K- M ave-M UN TED STATES PATENT FFICE.

TnoMAs J. HOGAN, or PITTSBURG, PENNSYLVANIA, ASSIGNOR TO THE WESTINGHOUSE AIR BRAKE COMPANY, OF sAME PLAcE.

AIR-BRAKE.

SPECIFICATION forming part of Letters Patent No. 433,594, dated August 5, 1890.

Application filed May 29, 1890- Serial No. 353,609. (No model.)

To all whom it may concern:

Be it known that I, THOMAS J. HOGAN, a citizen of the United States, residing at Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented or discovered certain new and useful Improvementsin Air- Brakes, of which improvements the following is a specification.

The object of my invention is to provide means for releasing the air from the trainpipe under each car, in applying the brakes, and exhausting the air so released to the brake-cylinder, said release of air and exhaust to the brake-cylinder being effected without the aid of an xi liary-reservoir pressu re.

A further object of my invention is to exhaust the air released from the train-pipe to the atmosphere when its flow to the brakecylinder is cut off or ceases.

In my present invention I employ a releasevalve under each car, which is operated by the variations of pressure in the pipe in which it is located, and which does not depend for its action on the pressure in the auxiliary reservoir, or on the movement of' the triple valve or other governing valve whose movement applies or releases the brakes by admitting air to or releasing air from the brakecylinder; but this release-valve I do not wish to claim specifically in this application, as it is claimed in my ,application, Serial No. 355,324, filed June 13, 1890.

The improvement set forth in this application, and for which I desire to secure Letters Patent, consists, broadly, of a combination of the release-valve referred to with means for exhausting the air released from the trainpipe into the brake-cylinder. -Italso includes means for closing the communication be tween the train-pipe release-valve and the brake-cylinder when the pressure in the brakecylinder is sufiicient to prevent the flow of air from the train-pipe into the brake-cylinder, or nearly so. The point at which this communication is closed and the flow checked may be fixed at any point desirable before the equalization of the pressure of the air in the brake-cylinder, and the air which is being released from the train-pipe.

My invention further consists of means to exhausting the air released from the trainpipe into the atmosphere when its flow to the brake-cylinder is cut off. By this means I cause the release from the train-pipe to be continuous and the reduction of pressure in the train-pipe to be quick and complete. By my invention I utilize a portion of the air which is released from the train-pipe in the brake-cylinder, thereby gaining increased power in making emergency stops, and then, instead of suddenly stopping the release and shutting'the air up in the train-pipe at a high pressure, I release it to the atmosphere, and this is done so quickly that the reduction of pressure in the train-pipe is as sudden and as great as if it were released directly to the atmosphere, and consequently the movements of the triple valves are quickened and made more nearly simultaneous.

I am aware that it is not new to exhaust the air from the train-pipe into the brake-cylinder; but my invention differs from all others that I know of,in being independentof the auxiliary-reservoir pressure or of the movement of the main or triple valve operating piston.

In all those devices which depend for their action on the auxiliary-reserveir pressure, or more directly on the movement of the triplevalve piston, the release-valve, whose object is to quicken the movement of the triple valve, is forced to wait for the triple valve to act before it has movement imparted to it, and then it is usually only opened when the triple valve is in the position where it is the object of the release-valve to cause it to be. Besides, if the release-valve is operated by the movement of the triple-valve piston its resistance is an additional resistance to the movement of the triple valve. My improvement differs from the devices referred to above in causing the release-valve to be operated by the air in the pipe in which it is placed, and by so doing making it independent of the auxiliary-reservoir pressure, so that it may act to release the air from the train- 5 pipe under circumstances which would cause the triple valves to move slowly and with too little force to open the release-valve, if operated by themsuch, for example, as a low pressure in the auxiliary reservoirs, which is always the case immediately after the brakes have been released. My release-valve may be operated at any time after a moderate pressure has been reached in the train-pipe, regardless of whether the auxiliary reservoirs are fully recharged or not. Besides, from its construction and location, it must act before and more easily than the triple valve, and the failure of the triple valve does not necessitate the failure of the release-valve; but the release-valve acts whether the triple valve does or not; but as these are features which are more fully brought out in my application, Serial No. 355,324,'filed June 13, 1890, referred to above, and as I do not wish to specifically claim the release-valve in this application, I will merely describe the means in connection with which I employ the release-valve for the purposes above stated, and the release-valve so far as it forms a part of my present invention. I wish it to be understood, however, that in this connection I do not desire to limit myself to any particular construction of re lease-valve, but only to one which is in its operation independent of the auxiliary-reservoir pressure.

In the accompanying drawings, Figure 1 is a general plan showing the arrangement of the main train-pipe auxiliary reservoir, release-valve, brake-cylinder, and the branch from the release-valve to the brake-cylinder;

Fig. 2, a section through the release-valve and its connection with the branch pipe to the brake-cylinder; Fig. 3, an elevation of the release-valve and a section through one form of the means for connecting it with the brake-cylinder.

The train-pipe 1 is connected by means of a T-coupling 9 under each car to the branch pipe 4:, leading to the triple valve 7, which has connections to the auxiliary reservoir 6 and the brake-cylinder 8. This is the usual arrangement in automatic fluid pressure brakes.

In my improvement I place the train-pipe release-valve 5 in the branch pipe near the main train-pipe and connect it so that it may exhaust through the device 2 and the pipe 3 (shown in Figs. 1 and 2) to the brake-cylin-' der, or it may be connected for the same purpose to the device shown in Fig.

In Fig. 2 the train-pipe-release valve casing 5 is connectedby the screw-threaded opening 20 to the T-coupling 9 in the main train-pipe 1, and at its other end by the opening 17 to the branch pipe 4:, which leads to the triple valve 7. Within the casing 5 of the release valve is a movable abutment or piston 13, having ports 33 through it, over which is placeda light flat disk valve 15, which opens against a light spring 22, to allow the air entering from the train-pipe to flow to the triple valve. The movement of this piston away from the train-pipe is checked by the stop 16, against which the stem 34 strikes. It is not necessarily always held in this position, but is free to move some distance away from the stop, and in making service stops, when the train-pipe pressure is reduced, the piston moves toward the train-pipe until the shoulder 36 strikes the valve 10, when its further movement is checked by the spring 18. The piston then will be in position to allow the air to pass around it through the cavity 35 in the wall of the casing. WVhen a great and sudden reduction of pressure is made, the.

piston moves sufficiently far and with sufficient force to compress the spring 18 and open the valve 10, thus allowing the air to escape through the passage 11, when it hits the valve 12 and passes through the pipe 3 to to the brakecylinder.

In Fig. 3 the same release-valveis shown in elevation with the passage 11- opening into the chamber 23 of a casing 32. In this device the air on entering the chamber 23 passes through the passage 24 and opening 31 to the brake-cylinder, and at the same time through passage 37 to the back of the abutment or diaphragm 30, which is connected to the rod 27, and as the area of diaphragm 30 is considerably greater than that of diaphragm 29 the pressure acting on diaphragm 30 is great enough to overcome that acting on the right side of diaphragm 29 and to compress the spring 28, thereby moving the valve 26 to the right and closing the port leading from chamber 23 to the passage 24 and opening the port 25, leading to the atmosphere from chamber 23. The parts are so adjusted that this will occur at about the same time that an ordinary check-valve-such as shown in Fig. 2- would close; but the parts may be so adjusted as to act sooner or later, the object being to stop the flow to the brake-cylinder before the brake-cylinder pressure is great enough to cause a backward flow. It will be seen that in Fig. 3 when the passage 24 is closed by the valve 26 the port or passage 25, which leads to the atmosphere, is opened, so that'the flow of air from the release-valve while it is shut off from the brake-cylinder is not checked, but is hastened by being opened to .the atmosphere, so that there is a sudden and great reduction of train-pipe pressure caused throughout the train. The space between the diaphragms 29 and 30 opens to the atmosphere through ports 45.

lVhile I employ a double diaphragm in the device shown in Fig. 3, it will readily be seen that any differential arrangement of piston or diaphragm may be used for the same purpose, and where I use the term abutment in my claims I intend itto include such devices.

What I claim as my invention, and desire to secure by Letters Patent, is

1. In an automatic fluid-pressure-brake mechanism, the combination of a train-pipe release-valve for releasing the air from the train-pipe under each car by a preliminary reduction of train-pipe pressure, said valve being independent of the auxiliary-reservoir pressure, and a passage from the release valve to the brake-cylinder, whereby the air released from the train-pipe may pass to the brake-cylinder.

2. In an automatic fluid pressure-brake mechanism, the combination of a train-pipe release-valve for releasing the air from the train -pipe by a preliminary reduction of train-pipe pressure, a movable abutment operated by variations of pressure in the pipe in which it is located independentof the auxiliary-reservoir pressure or the movement of the triple valve, and a passage from the release-valve to the brake-cylinder.

3. In automatic fluid-pressure brakes, the

combination, with a train-pipe release-valve,

of a movable abutment, the space on one side of which communicates with the brake-cylinder, and a valve operated by the abutment to open and close a port by which air may pass from the train-pipe release-valve to the atmosphere.

4. In automatic fluid-pressure brakes, the combination of atrain-pipe release-valve, pas- "sages from the train-pipe release-valve to the brake-cylinder and to the atmosphere, and a movable abutment whose movement controls the passages to the brake-cylinder and atmosphere.

5 In automatic fluid-pressure brakes, the combination of a train-pipe release-valve, passages from the train-pipe release-valve to the brake-cylinder and to the atmosphere, and a movable abutment whose movement operates a valve controlling the passages to the brake cylinder and atmosphere.

6. In a fluid pressure automatic brake mechanism, the combination of a valve which opens on a reduction of pressure in the trainpipe to allow the air to escape from the trainpipe, and avalve controlling a port by which the said air may pass to the atmosphere, said valve being operated to open the port leading to the atmosphere by the pressure of the escaping air on a movable abutment.

7. In a fiuidpressure automatic brake mechanism, the combination of a valve for releasing the air from the train-pipe on a reduction of pressure in the train-pipe, and valve mechanism controlling ports by which the air released from the train-pipe may pass to the brake-cylinder or to the atmosphere.

8. In afiuid-pressure-brake mechanism, the combination of a train-pipe release-valve, passages leading from the train-pipe releasevalve to the brake-cylinder and to the atmosphere, and a movable abutment which is operated to close the passage to the brake-cylinder and open the passage to the atmosphere by the pressure in the passage to the brakecylinder.

9. In a fluidpressure automatic brake mechanism, the combination of a train-pipe release-valve, passages leading from the trainpipe release-valve to the brake-cylinder and to the atmosphere, and a movable abutment which is operated to close the passage to the brake-cylinder and open the passage to the atmosphere after a portion of the air has escaped from the train-pipe to the brake-cylinder.

10. The combination, with a conduit pipe or pipes, of a fluid-pressure-brake mechanism, a vent or release-valve therein, passages leading thence to the brake-cylinder and to the open air, a valve mechanism governing the flow of air through such passages, wherebya portion of the air so vented or released shall pass first to the brake-cylinder and the remainder to the open air, and a movable abutment subject to variations of air-pressure for shifting automatically the valve mechanism which directs such flow, substantially as described.

11. The method of operating fluid-pressure automatic brakes, which consists in releasing the air from the train-pipe under each car and allowing a portion to pass to the brakecylinder, then cutting off the flow from the train-pipe to the brakecylinder, and opening a passage from the train-pipe to the atmosphere.

In testimony whereof I have hereunto set my hand.

THOMAS J. HOGAN.

.Witnesses:

R, H. WrrIrrLEsEY, F. E. GAI'IHER. 

